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4f5dd394 LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
11c3a366 TA |
22 | #include <errno.h> |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | ||
b5efdb8a | 26 | #include "alloc-util.h" |
e4e73a63 LP |
27 | #include "escape.h" |
28 | #include "hexdecoct.h" | |
11c3a366 | 29 | #include "macro.h" |
4f5dd394 | 30 | #include "utf8.h" |
4f5dd394 | 31 | |
4f5dd394 LP |
32 | size_t cescape_char(char c, char *buf) { |
33 | char * buf_old = buf; | |
34 | ||
35 | switch (c) { | |
36 | ||
37 | case '\a': | |
38 | *(buf++) = '\\'; | |
39 | *(buf++) = 'a'; | |
40 | break; | |
41 | case '\b': | |
42 | *(buf++) = '\\'; | |
43 | *(buf++) = 'b'; | |
44 | break; | |
45 | case '\f': | |
46 | *(buf++) = '\\'; | |
47 | *(buf++) = 'f'; | |
48 | break; | |
49 | case '\n': | |
50 | *(buf++) = '\\'; | |
51 | *(buf++) = 'n'; | |
52 | break; | |
53 | case '\r': | |
54 | *(buf++) = '\\'; | |
55 | *(buf++) = 'r'; | |
56 | break; | |
57 | case '\t': | |
58 | *(buf++) = '\\'; | |
59 | *(buf++) = 't'; | |
60 | break; | |
61 | case '\v': | |
62 | *(buf++) = '\\'; | |
63 | *(buf++) = 'v'; | |
64 | break; | |
65 | case '\\': | |
66 | *(buf++) = '\\'; | |
67 | *(buf++) = '\\'; | |
68 | break; | |
69 | case '"': | |
70 | *(buf++) = '\\'; | |
71 | *(buf++) = '"'; | |
72 | break; | |
73 | case '\'': | |
74 | *(buf++) = '\\'; | |
75 | *(buf++) = '\''; | |
76 | break; | |
77 | ||
78 | default: | |
79 | /* For special chars we prefer octal over | |
80 | * hexadecimal encoding, simply because glib's | |
81 | * g_strescape() does the same */ | |
82 | if ((c < ' ') || (c >= 127)) { | |
83 | *(buf++) = '\\'; | |
84 | *(buf++) = octchar((unsigned char) c >> 6); | |
85 | *(buf++) = octchar((unsigned char) c >> 3); | |
86 | *(buf++) = octchar((unsigned char) c); | |
87 | } else | |
88 | *(buf++) = c; | |
89 | break; | |
90 | } | |
91 | ||
92 | return buf - buf_old; | |
93 | } | |
94 | ||
a5ef3638 | 95 | char *cescape_length(const char *s, size_t n) { |
4f5dd394 | 96 | const char *f; |
a5ef3638 | 97 | char *r, *t; |
4f5dd394 | 98 | |
a5ef3638 | 99 | assert(s || n == 0); |
4f5dd394 LP |
100 | |
101 | /* Does C style string escaping. May be reversed with | |
102 | * cunescape(). */ | |
103 | ||
a5ef3638 | 104 | r = new(char, n*4 + 1); |
4f5dd394 LP |
105 | if (!r) |
106 | return NULL; | |
107 | ||
a5ef3638 | 108 | for (f = s, t = r; f < s + n; f++) |
4f5dd394 LP |
109 | t += cescape_char(*f, t); |
110 | ||
111 | *t = 0; | |
112 | ||
113 | return r; | |
114 | } | |
115 | ||
a5ef3638 LP |
116 | char *cescape(const char *s) { |
117 | assert(s); | |
118 | ||
119 | return cescape_length(s, strlen(s)); | |
120 | } | |
121 | ||
3565e095 | 122 | int cunescape_one(const char *p, size_t length, uint32_t *ret, bool *eight_bit) { |
4f5dd394 LP |
123 | int r = 1; |
124 | ||
125 | assert(p); | |
126 | assert(*p); | |
127 | assert(ret); | |
128 | ||
3565e095 ZJS |
129 | /* Unescapes C style. Returns the unescaped character in ret. |
130 | * Sets *eight_bit to true if the escaped sequence either fits in | |
131 | * one byte in UTF-8 or is a non-unicode literal byte and should | |
132 | * instead be copied directly. | |
133 | */ | |
4f5dd394 LP |
134 | |
135 | if (length != (size_t) -1 && length < 1) | |
136 | return -EINVAL; | |
137 | ||
138 | switch (p[0]) { | |
139 | ||
140 | case 'a': | |
141 | *ret = '\a'; | |
142 | break; | |
143 | case 'b': | |
144 | *ret = '\b'; | |
145 | break; | |
146 | case 'f': | |
147 | *ret = '\f'; | |
148 | break; | |
149 | case 'n': | |
150 | *ret = '\n'; | |
151 | break; | |
152 | case 'r': | |
153 | *ret = '\r'; | |
154 | break; | |
155 | case 't': | |
156 | *ret = '\t'; | |
157 | break; | |
158 | case 'v': | |
159 | *ret = '\v'; | |
160 | break; | |
161 | case '\\': | |
162 | *ret = '\\'; | |
163 | break; | |
164 | case '"': | |
165 | *ret = '"'; | |
166 | break; | |
167 | case '\'': | |
168 | *ret = '\''; | |
169 | break; | |
170 | ||
171 | case 's': | |
172 | /* This is an extension of the XDG syntax files */ | |
173 | *ret = ' '; | |
174 | break; | |
175 | ||
176 | case 'x': { | |
177 | /* hexadecimal encoding */ | |
178 | int a, b; | |
179 | ||
180 | if (length != (size_t) -1 && length < 3) | |
181 | return -EINVAL; | |
182 | ||
183 | a = unhexchar(p[1]); | |
184 | if (a < 0) | |
185 | return -EINVAL; | |
186 | ||
187 | b = unhexchar(p[2]); | |
188 | if (b < 0) | |
189 | return -EINVAL; | |
190 | ||
191 | /* Don't allow NUL bytes */ | |
192 | if (a == 0 && b == 0) | |
193 | return -EINVAL; | |
194 | ||
3565e095 ZJS |
195 | *ret = (a << 4U) | b; |
196 | *eight_bit = true; | |
4f5dd394 LP |
197 | r = 3; |
198 | break; | |
199 | } | |
200 | ||
201 | case 'u': { | |
202 | /* C++11 style 16bit unicode */ | |
203 | ||
204 | int a[4]; | |
205 | unsigned i; | |
206 | uint32_t c; | |
207 | ||
208 | if (length != (size_t) -1 && length < 5) | |
209 | return -EINVAL; | |
210 | ||
211 | for (i = 0; i < 4; i++) { | |
212 | a[i] = unhexchar(p[1 + i]); | |
213 | if (a[i] < 0) | |
214 | return a[i]; | |
215 | } | |
216 | ||
217 | c = ((uint32_t) a[0] << 12U) | ((uint32_t) a[1] << 8U) | ((uint32_t) a[2] << 4U) | (uint32_t) a[3]; | |
218 | ||
219 | /* Don't allow 0 chars */ | |
220 | if (c == 0) | |
221 | return -EINVAL; | |
222 | ||
3565e095 | 223 | *ret = c; |
4f5dd394 LP |
224 | r = 5; |
225 | break; | |
226 | } | |
227 | ||
228 | case 'U': { | |
229 | /* C++11 style 32bit unicode */ | |
230 | ||
231 | int a[8]; | |
232 | unsigned i; | |
dcd12626 | 233 | uint32_t c; |
4f5dd394 LP |
234 | |
235 | if (length != (size_t) -1 && length < 9) | |
236 | return -EINVAL; | |
237 | ||
238 | for (i = 0; i < 8; i++) { | |
239 | a[i] = unhexchar(p[1 + i]); | |
240 | if (a[i] < 0) | |
241 | return a[i]; | |
242 | } | |
243 | ||
dcd12626 LP |
244 | c = ((uint32_t) a[0] << 28U) | ((uint32_t) a[1] << 24U) | ((uint32_t) a[2] << 20U) | ((uint32_t) a[3] << 16U) | |
245 | ((uint32_t) a[4] << 12U) | ((uint32_t) a[5] << 8U) | ((uint32_t) a[6] << 4U) | (uint32_t) a[7]; | |
4f5dd394 LP |
246 | |
247 | /* Don't allow 0 chars */ | |
248 | if (c == 0) | |
249 | return -EINVAL; | |
250 | ||
251 | /* Don't allow invalid code points */ | |
252 | if (!unichar_is_valid(c)) | |
253 | return -EINVAL; | |
254 | ||
3565e095 | 255 | *ret = c; |
4f5dd394 LP |
256 | r = 9; |
257 | break; | |
258 | } | |
259 | ||
260 | case '0': | |
261 | case '1': | |
262 | case '2': | |
263 | case '3': | |
264 | case '4': | |
265 | case '5': | |
266 | case '6': | |
267 | case '7': { | |
268 | /* octal encoding */ | |
269 | int a, b, c; | |
dcd12626 | 270 | uint32_t m; |
4f5dd394 LP |
271 | |
272 | if (length != (size_t) -1 && length < 3) | |
273 | return -EINVAL; | |
274 | ||
275 | a = unoctchar(p[0]); | |
276 | if (a < 0) | |
277 | return -EINVAL; | |
278 | ||
279 | b = unoctchar(p[1]); | |
280 | if (b < 0) | |
281 | return -EINVAL; | |
282 | ||
283 | c = unoctchar(p[2]); | |
284 | if (c < 0) | |
285 | return -EINVAL; | |
286 | ||
287 | /* don't allow NUL bytes */ | |
288 | if (a == 0 && b == 0 && c == 0) | |
289 | return -EINVAL; | |
290 | ||
291 | /* Don't allow bytes above 255 */ | |
dcd12626 | 292 | m = ((uint32_t) a << 6U) | ((uint32_t) b << 3U) | (uint32_t) c; |
4f5dd394 LP |
293 | if (m > 255) |
294 | return -EINVAL; | |
295 | ||
296 | *ret = m; | |
3565e095 | 297 | *eight_bit = true; |
4f5dd394 LP |
298 | r = 3; |
299 | break; | |
300 | } | |
301 | ||
302 | default: | |
303 | return -EINVAL; | |
304 | } | |
305 | ||
306 | return r; | |
307 | } | |
308 | ||
309 | int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret) { | |
310 | char *r, *t; | |
311 | const char *f; | |
312 | size_t pl; | |
313 | ||
314 | assert(s); | |
315 | assert(ret); | |
316 | ||
317 | /* Undoes C style string escaping, and optionally prefixes it. */ | |
318 | ||
319 | pl = prefix ? strlen(prefix) : 0; | |
320 | ||
321 | r = new(char, pl+length+1); | |
322 | if (!r) | |
323 | return -ENOMEM; | |
324 | ||
325 | if (prefix) | |
326 | memcpy(r, prefix, pl); | |
327 | ||
328 | for (f = s, t = r + pl; f < s + length; f++) { | |
329 | size_t remaining; | |
dcd12626 | 330 | uint32_t u; |
3565e095 | 331 | bool eight_bit = false; |
4f5dd394 LP |
332 | int k; |
333 | ||
334 | remaining = s + length - f; | |
335 | assert(remaining > 0); | |
336 | ||
337 | if (*f != '\\') { | |
338 | /* A literal literal, copy verbatim */ | |
339 | *(t++) = *f; | |
340 | continue; | |
341 | } | |
342 | ||
343 | if (remaining == 1) { | |
344 | if (flags & UNESCAPE_RELAX) { | |
345 | /* A trailing backslash, copy verbatim */ | |
346 | *(t++) = *f; | |
347 | continue; | |
348 | } | |
349 | ||
350 | free(r); | |
351 | return -EINVAL; | |
352 | } | |
353 | ||
3565e095 | 354 | k = cunescape_one(f + 1, remaining - 1, &u, &eight_bit); |
4f5dd394 LP |
355 | if (k < 0) { |
356 | if (flags & UNESCAPE_RELAX) { | |
357 | /* Invalid escape code, let's take it literal then */ | |
358 | *(t++) = '\\'; | |
359 | continue; | |
360 | } | |
361 | ||
362 | free(r); | |
363 | return k; | |
364 | } | |
365 | ||
3565e095 ZJS |
366 | f += k; |
367 | if (eight_bit) | |
368 | /* One byte? Set directly as specified */ | |
369 | *(t++) = u; | |
4f5dd394 | 370 | else |
3565e095 | 371 | /* Otherwise encode as multi-byte UTF-8 */ |
4f5dd394 | 372 | t += utf8_encode_unichar(t, u); |
4f5dd394 LP |
373 | } |
374 | ||
375 | *t = 0; | |
376 | ||
377 | *ret = r; | |
378 | return t - r; | |
379 | } | |
380 | ||
381 | int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret) { | |
382 | return cunescape_length_with_prefix(s, length, NULL, flags, ret); | |
383 | } | |
384 | ||
385 | int cunescape(const char *s, UnescapeFlags flags, char **ret) { | |
386 | return cunescape_length(s, strlen(s), flags, ret); | |
387 | } | |
388 | ||
389 | char *xescape(const char *s, const char *bad) { | |
390 | char *r, *t; | |
391 | const char *f; | |
392 | ||
393 | /* Escapes all chars in bad, in addition to \ and all special | |
394 | * chars, in \xFF style escaping. May be reversed with | |
395 | * cunescape(). */ | |
396 | ||
397 | r = new(char, strlen(s) * 4 + 1); | |
398 | if (!r) | |
399 | return NULL; | |
400 | ||
401 | for (f = s, t = r; *f; f++) { | |
402 | ||
403 | if ((*f < ' ') || (*f >= 127) || | |
404 | (*f == '\\') || strchr(bad, *f)) { | |
405 | *(t++) = '\\'; | |
406 | *(t++) = 'x'; | |
407 | *(t++) = hexchar(*f >> 4); | |
408 | *(t++) = hexchar(*f); | |
409 | } else | |
410 | *(t++) = *f; | |
411 | } | |
412 | ||
413 | *t = 0; | |
414 | ||
415 | return r; | |
416 | } | |
417 | ||
418 | static char *strcpy_backslash_escaped(char *t, const char *s, const char *bad) { | |
419 | assert(bad); | |
420 | ||
421 | for (; *s; s++) { | |
422 | if (*s == '\\' || strchr(bad, *s)) | |
423 | *(t++) = '\\'; | |
424 | ||
425 | *(t++) = *s; | |
426 | } | |
427 | ||
428 | return t; | |
429 | } | |
430 | ||
431 | char *shell_escape(const char *s, const char *bad) { | |
432 | char *r, *t; | |
433 | ||
434 | r = new(char, strlen(s)*2+1); | |
435 | if (!r) | |
436 | return NULL; | |
437 | ||
438 | t = strcpy_backslash_escaped(r, s, bad); | |
439 | *t = 0; | |
440 | ||
441 | return r; | |
442 | } | |
443 | ||
444 | char *shell_maybe_quote(const char *s) { | |
445 | const char *p; | |
446 | char *r, *t; | |
447 | ||
448 | assert(s); | |
449 | ||
450 | /* Encloses a string in double quotes if necessary to make it | |
451 | * OK as shell string. */ | |
452 | ||
453 | for (p = s; *p; p++) | |
454 | if (*p <= ' ' || | |
455 | *p >= 127 || | |
456 | strchr(SHELL_NEED_QUOTES, *p)) | |
457 | break; | |
458 | ||
459 | if (!*p) | |
460 | return strdup(s); | |
461 | ||
462 | r = new(char, 1+strlen(s)*2+1+1); | |
463 | if (!r) | |
464 | return NULL; | |
465 | ||
466 | t = r; | |
467 | *(t++) = '"'; | |
468 | t = mempcpy(t, s, p - s); | |
469 | ||
470 | t = strcpy_backslash_escaped(t, p, SHELL_NEED_ESCAPE); | |
471 | ||
472 | *(t++)= '"'; | |
473 | *t = 0; | |
474 | ||
475 | return r; | |
476 | } |